1. Field of the Invention
The invention relates to a telephone apparatus which can execute a speech communication via either one of a plurality of external lines.
2. Description of the Related Background Art
In conventional telephone exchanges, there is a telephone exchange in which in order to improve the operating efficiency when an external lines are transferred or the like, external buttons and external lamps in each for the same number of external lines are provided in an extension telephone and states of external lines are notified by the flickering of the selected external line lamp, color, or the like.
In the above conventional apparatus, however, there is a problem such that when the number of external lines to be enclosed in the extension telephone increases, the number of external line buttons and the number of external line lamps also increases, so that the operating efficiency deteriorates and an area of the operating section increases.
The above problem is particularly difficult in a slave cordless telephone.